Esterified/Free Ratio details
What Esterified/Free Ratio shows
Carnitine helps carry fatty acids into your cells' mitochondria so they can be burned for energy. In blood it exists as free carnitine and as esterified carnitine (acylcarnitines), where carnitine is bound to other molecules. This ratio is calculated by dividing the esterified carnitine result by the free carnitine result. It helps show whether carnitine is being tied up by excess acyl groups, which can happen in certain inherited metabolic disorders, with some medicines, or in kidney disease. A higher ratio can point to relative carnitine insufficiency, even when total carnitine looks normal. It is interpreted alongside total and free carnitine and your clinical picture.
Tests that include Esterified/Free Ratio
Serum carnitine analysis is useful in the diagnosis and monitoring of patients with carnitine deficiency (either primary or secondary). Primary carnitine deficiency is an autosomal recessively inherited genetic condition that affects carnitine uptake by cells and tissues through a defect in the plasma membrane carnitine transporter. Secondary carnitine deficiency can be seen in some disease states or in patients on carnitine-poor diets, but is also seen in a number of metabolic disorders. In these disorders, carnitine complexes with the accumulated substrate of the blocked metabolic step, and the resulting acylcarnitine ester is excreted in the urine, leading to a depletion of carnitine in the patient.
- Carnitine, Esters Shows the amount of carnitine bound to fatty acids in your blood, calculated from total and free carnitine, used to assess carnitine and fat metabolism.
- Carnitine, Free Measures free, unbound carnitine in your blood, which helps move fats into cells for energy, to look for carnitine deficiency.
- Carnitine, Total Measures total carnitine in your blood, both free and bound forms, to check for carnitine deficiency and look at fat metabolism.
- Esterified/Free Ratio A ratio calculated from esterified (acyl) carnitine and free carnitine in serum, used to help assess carnitine status and how fats are being processed.
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